Performance Impact of Adding Parameter to User Control

Question

We run a site that uses master pages and creates its navigation using the built-in ASP.NET sitemap provider. The navigation presents itself as a CSS rollover menu. Our client would like to show the entire menu, including 2 levels of sub-menus, to one audience while restricting a different audience to a single level of navigation. My code knows the audience based on a cookie value.

Rather than duplicate the user control or master page, I would like to add a parameter to the user control that would show or hide the lower levels of navigation.

How should I implement this to maximize performance? The article below explained some of the concepts, but I would like to hear from people who have done this in production.

Caching Multiple Versions of a User Control by Using Declarative Attributes http://msdn.microsoft.com/en-us/library/53a3xxk8%28v=VS.71%29.aspx

Here's the code.

private void GetNodes(XmlNode node, int intDesiredDepth, int intNodeDepth, StringBuilder sb)
{
    if (node is XmlElement)
    {
        intNodeDepth++;
        string strFirstUL = "";

        if (intNodeDepth == 1)
        {
            strFirstUL = " id='nav'";
        }

        if (intNodeDepth <= intDesiredDepth)
        {
            if (node.Attributes.Count > 0)
            {
                GetAttributes(node, sb, intDesiredDepth);
            }

            if (node.HasChildNodes & intNodeDepth < intDesiredDepth)
            {

                sb.Append("<ul" + strFirstUL + ">");

                foreach (XmlNode child in node.ChildNodes)
                {
                    GetNodes(child, intDesiredDepth, intNodeDepth, sb);
                }

                sb.Append("</ul></li>");
            }

        }

    }

    ltlNav.Text = sb.ToString();
    return;
}